Voltage measurement devices for medium and high voltage applications use resistive and/or capacitive dividers for voltage measurement and/or for protection purposes of switchgear arrangements, for example. Such devices, which operate at medium or at high voltage levels, can be exposed to a strong electric field which, being placed in close proximity, can influence measured quantities mainly in case of low-power outputs or introduce high dielectric stress on insulating material or on a surface of such equipment. In case of outdoor installations and under humid conditions, further influences could be observed, which can change electric field distribution thus causing error to measured voltage level or causing corona on the surface of devices or increased partial discharge level within devices.
FIG. 2 illustrates a voltage divider in accordance with a prior art implementation. The voltage divider includes an insulating body, which houses high voltage impedance that is connected to high voltage impedance at one end and to low-voltage impedance at the other end. Low-voltage impedance should be connected to the ground. Output of such impedance divider is done via two wires and/or a cable.
The prior art arrangement is subject to a higher susceptibility to parasitic capacitances and probability to change the accuracy of a measured voltage, which can lead to inaccurate values for protection and/or measurement purposes occurs.